The relationship between hearing impairment and cognitive function: a meta-analysis in adults

Area of Science:

• Neuroscience
• Public Health
• Gerontology

Background:

• Hearing loss affects over 1.23 billion people globally.
• A potential negative impact of hearing impairment on cognition, including faster cognitive decline and increased dementia risk, has been proposed but is not universally accepted.
• Existing evidence requires systematic examination to clarify the hearing-cognition relationship.

Purpose of the Study:

• To conduct a meta-analysis examining the evidence base for the relationship between hearing and cognition.
• To investigate whether cognition is poorer in individuals with untreated or treated hearing impairment compared to normal hearing.
• To assess the association between the degree of hearing impairment and cognitive function, the impact of hearing interventions, and the differential effects across cognitive domains.

Main Methods:

• A systematic review of published and grey literature was performed.
• Meta-analyses were conducted on findings from included studies.
• Studies involving adults with and without hearing impairment, examining the hearing-cognition relationship, were included.

Main Results:

• Cognition was significantly poorer in individuals with both untreated and treated hearing impairment compared to normal hearers.
• A significant association was found between the degree of cognitive deficit and the degree of hearing impairment in both untreated and treated groups.
• Hearing intervention demonstrated a significant improvement in cognition, and hearing impairment affected all cognitive domains.

Conclusions:

• The meta-analysis suggests a significant association between hearing impairment and cognitive problems.
• However, the conclusion may be premature due to study diversity, small sample sizes, and inadequate control for confounding health factors.